次显微金在黄铁矿和毒砂中的赋存状态新探讨

重新认以了含金黄铁矿、含金毒砂中次显微金的电子顺磁共振实验和溶解实验的结果。指出它们均不能作为存在类质同象金的证据，含金黄铁矿和含金毒砂中的顺磁中心可能由As、S之间的类质同象取代引起；硝酸溶解金的载体矿物后溶液中出现的Au3-离子可能来自金的硫化物的微包裹体金。进而认为含金黄铁矿和含金每秒中不可能存在类质同象金。     

中国对虾球形病毒的初步研究

用电子显微镜对中国对虾进行病毒的检测，发现一种新的球形病毒，这种病毒直径约８０～１００ｎｍ，具有包涵体，形态上有两种电子密度，球形病毒数量较多，分布在细胞质中，细胞核中没有发现，主要侵染对虾的肠、鳃、肌肉、肝胰腺等组织；宿主细胞的病理变化表现为内质网水肿，线粒体内嵴肿胀及局部溶解，酶原颗粒和粘蛋白原变性等；球形病毒与杆状病毒混合感染是对虾爆发流行病的主要病因     

太平洋牡蛎配子和精子人卵的扫描电镜观察及胚胎发育的初步研究

通过扫描电镜观察,太平洋牡蛎精子由头部、中段和尾段组成.精子全长约21.6μm,尾段长约18.2μm,末端观察到"针眼"样结构;头部最大处的直径约2.6μm;中段直径约1.1μm;未成熟精子尾段中部出现膨大,该处直径约0.3μm.卵呈梨形;卵的直径约为41.9μm.卵表面有微绒毛组成的皱折结构,可见卵黄膜孔.卵质收回时,在卵表面卵柄处可见明显的树枝状结构.受精后,受精卵表面的卵黄膜剥离处可见较多数量的皮质小泡.在水温21.2～23.5℃,精卵混合34min时,释时出第1极体;1h22min时,放出第2极体;21h55min时,胚胎发育至初期D形幼虫.     

一种对虾杆状病毒形态及形态发生的研究

以患病死亡的甲壳上具白斑的斑节对虾(Penaeusmonodon)虾头及从中提取的病毒悬液分别感染中国对虾(Penaeuschinensis)幼虾及日本对虾(Penaeusjaponicus)。感染后此2种对虾均发病死亡 ,且甲壳上均有白斑。电镜下对人工感染的中国对虾幼虾及日本对虾的组织器官进行观察发现了大量的病毒。此病毒为杆状 ,具囊膜 ,无包涵体 ,大小为295nm×105nm。此病毒的形态发生起始于细胞核 ,并可分为4个阶段 :病毒基质的形成、囊膜的形成、病毒的装配和完整的病毒粒子的形成。病毒的装配过程是与其大量迅速繁殖相适应的。     

Preservation of old U–Th–Pb ages in shielded monazite: example from the Beni Bousera Hercynian kinzigites (Morocco)

Four samples from the metamorphic aureole around the Beni Bousera ultramafic massif were studied in detail for U–Th–Pb electron microprobe dating on monazite. The samples include three meta-sedimentary granulites (kinzigites), collected at variable distance from the peridotites, and one kyanite-bearing leucosome in the kinzigite. Two types of monazite were identified in thin section, using SEM. The main population consists of interstitial grains, 20–70  μ m in size, while the second population consists of small grains (<20  μ m), included in garnet. A total of 64 U–Th–Pb electron microprobe measurements on 53 monazite crystals were undertaken. Most crystals have a Pb content lower than the Pb detection limit, indicating that they crystallized, or were reset, during a young event, probably Cainozoic in age. Few crystals, all entirely included in garnet, have Hercynian age, the best estimate of which is 284±27 Ma. This is a direct demonstration of the shielding effect of garnet for the U–Th–Pb system in monazite. The grains in inclusion in garnet are not reset by the post-Hercynian events, despite the high temperature reached at this time (>850 °C). Thus, the monazite closure temperature depends on its textural position in the host rock. The data also show that a Hercynian event occurred in the Beni Bousera granulitic metapelites, which equates with a high- P , high- T  event. The emplacement of the peridotite in the Cainozoic may be linked a low- P , high- T  event, followed by a low- P , low- T  retrogression. These two events reset the U–Th–Pb system in almost all monazite grains, except for the few crystals shielded by garnet.     

小湾水电站低高程坝基开挖卸荷松弛机理试验研究

小湾电站低高程坝基开挖过程中,表层岩体卸荷松弛强烈,主要形式有沿已有裂隙地错动、张开和扩展,及因新生破裂而松弛。后者主要包括:葱皮现象、板裂现象和岩爆现象。试验测试表明,开挖面附近微新岩石为坚硬极坚硬岩石,但其初始损伤明显,其损伤发展启动应力在5.2~12.4MPa之间,抗拉强度在3~6MPa之间,这是坝基表层岩体卸荷松弛强烈的物质基础;坝基面爆破开挖的应力集中和爆炸作用影响是坝基岩体卸荷松弛强烈的岩石力学环境条件。     

用经验正交函数构造武汉地区电子浓度总含量的经验模式

本文利用经验正交函数（Empirical Orthogonal Function, 简称EOF）分析了武汉电离层台站一个太阳黑子周期（1980年4月～1990年12月）的实测电离层电子浓度总含量（TEC）资料,在此基础上构建了一个武汉地区的TEC月中值的经验模式.结果表明：（1）以EOF分析观测数据具有一定的物理意义,其基函数表征TEC的日变化,系数表征TEC的长期变化;（2）EOF技术展开收敛速度快,很少数低阶项即能反映TEC的主要变化,采用经验正交函数建模可以用较少的参数表征较复杂的物理过程.此外,本文还就TEC模式的外部驱动量的改进问题作了一些探讨,发现用F107A（107cm太阳辐射通量F107的81天滑动平均值）作TEC建模的外部驱动量能够更好地提高EOF模式的精度和稳定性.     

Micropore structure characteristics and water distribution in a coalbed methane reservoir

Microscopic pore structure and water distribution are important and fundamental parameters for coalbed methane reservoir characterisation. These are closely related to the calculation/interpretation of other critical parameters, such as permeability and flow capacity. In this study, scanning electron microscopy, low-pressure nitrogen gas adsorption, nuclear magnetic resonance spectroscopy, and theoretical calculations were used to study the pore structure characteristics and water distribution of Zhaozhuang coal mine in the southeastern Qinshui Basin, PR China. The results show that the pore radius ranges from 2.066 to 594.045?nm, mainly classified as micropores and transitional pores. The micropores significantly contribute to the total pore volume. The adsorption pores (micropores and transitional pores) contribute the most to the total specific surface area. The T₂ spectrum distributions of saturated water samples show two peaks. The first T₂ spectrum peak is related to adsorption pores, whereas the second T₂ spectrum peak is related to seepage pores. The seepage pores were not well developed as the adsorption pores. Most adsorption pores are saturated with irreducible water that could not be discharged by centrifugation, whereas the seepage pores are saturated with movable water that could be completely discharged by centrifugation. The T₂ cutoff method was used to calculate the irreducible water saturation, and the irreducible water saturation of the sample was ≥90%. The irreducible water was mainly distributed in the micropores, and some of the irreducible water was distributed in the transitional pores. The irreducible water that remains in the pores can cause reservoir damage.     

冻结作用对青藏红黏土及兰州粉土微观结构的影响分析

冻土微观孔隙特征是决定冻土体一系列物理、力学性质的基本参数,冻土中存在的冰晶体其体积受温度影响发生变化会影响到冻土的土体微观结构及孔隙特质发生变化。利用可用于负温冻土观测的新型扫描电镜,通过对青藏红黏土及兰州粉土不同初始条件下的土样冻结前后微观结构进行研究分析。结果表明：冻结作用发生后,冰晶生长对周围土颗粒产生挤压作用,导致周围土颗粒的移动和结构破坏,土中大孔隙的数量增多,加之周围小孔隙补给大孔隙中的冰晶进一步生长,出现局部个别大孔隙体积增大,小孔隙体积缩小的现象,表现在孔隙率上为土体在冻结后孔隙率减小;此外,对于粒径级配不同的土体而言,冻结作用对细颗粒土的土体孔隙的尺寸、形态以及排列方式等方面的影响均大于粗颗粒土;同样,初始含水率决定了冻结作用发生后参与改变土体微观结构的冰晶体生长的"量"的大小,在冻结作用对土体结构性破坏的过程中起重要作用。研究成果定量揭示了冻结作用对不同初始条件下的土体微观结构的影响,为研究冻土宏观力学特性和冻胀机制等提供了理论基础与和试验支撑。     

Classifying chalk microtextures: Sedimentary versus diagenetic origin (Cenomanian–Santonian,Paris Basin,France)

Microtexture describes the type of particles and their arrangement in matrix samples at scanning electron microscopy scale. Although a microtexture classification exists for micritic limestone, it cannot be directly applied to chalk. This study therefore proposes a classification of chalk microtextures and discusses the origin of microtexture variability. Chalk was sampled at thirteen spatio‐temporal locations along the coastline of northern France (Cenomanian–Santonian). Four criteria are defined to describe, characterize and determine chalk matrix microtexture: (i) mineralogical content; (ii) biogenic fraction; (iii) micritic fraction; and (iv) cement fraction. From these criteria, two major groups are defined: Pure Chalk Microtexture Group, with seven classes, and Impure Chalk Microtexture Group, divided into two subgroups: Argillaceous Microtexture with four classes and Siliceous Microtexture with two classes. Microtexture variability is related both to initial sedimentation and to diagenesis. Sedimentological conditions (for example, climate and distance from shore) affect chalk composition (carbonate content and type of insoluble particles), thus influencing microtexture. Changes in Pure Chalk Microtexture are the result of increasing diagenetic intensity. This classification can also be used to characterize the microtexture of subsurface chalk reservoirs. Reservoir quality depends on the petrophysical and mechanical properties of reservoir rocks, which can be better understood by exploring their sedimentary and diagenetic history, revealed by the study of chalk microtexture variability.